1. Field of the Invention
The present invention relates to a transmission electron microscope (hereinafter referred to as TEM) sample marked with self-identifying information in a coded manner, and a TEM sample management system constructed between a focused ion beam (hereinafter referred to as FIB) device for producing the sample and a TEM for observing the sample.
2. Description of the Related Art
Making of semiconductor sliced samples for TEM observation by thin-processing using an FIB device is well-known. A method where a small part is cut-out mechanically from a wafer-shaped sample and this is processed to be thin and a method where etching processing is carried out on a wafer as is so as to extract a thin sample are well-known. The present invention relates to TEM samples made using the latter method. This TEM sample manufacturing method is as follows. First, a protective deposition film is formed by irradiating a processing portion shown in FIG. 4A with an ion beam while ejecting source gas using a gas gun. As shown in FIG. 4B, a trench is then dug by irradiating a FIB from above the surface of the sample by etching processing at the rear side of an observation slice, and in a similar method shown in FIG. 4C, digging out takes place using etching processing at a front side of the observation slice. Namely, a square front hole and rear hole are made on either side of thin slice for observation using an FIB device. The size of the front hole is of a size capable of enabling observation of the observation slice at the time of tilting the sample table with a Scanning Ion Microscope (hereinafter referred to as a “SIM”), with the rear hole being of such a size that the width is the same as the front hole but the depth is in the order of two thirds that of the front hole. As the observation surface is damaged by the digging processing, finishing processing is carried out while suppressing beam current and the surface is polished. Next, the sample surface is tilted, and peripheral parts of the sample thin-processed as an observation slice as shown in FIG. 4D are irradiated with a focused ion beam as shown by the arrow so as to carry out cutting processing (bottom cutting). Then, as shown in FIG. 5A–5D, a manipulator (glass probe) is operated (FIG. 5A), this cut sample(sample chip) is separated from the sample body (FIG. 5B), and is moved so as to be positioned on a mesh (150 mesh) provided with a collodion film (FIG. 5C). The cut sample is then attached onto the mesh surface (FIG. 5D), and making of the sample for TEM observation is completed. The completed sample is what the cut sample with sides in the order of 10 μm is fixed to a mesh base of diameter of approximately 3 mm, and this handling management is troublesome due to the sample being extremely small in size.
There has therefore been a demand for development of a more reasonable management means for handling TEM samples that are extremely small in size under these kinds of conditions. A convenient method for accessing locations to be observed in detail on the microscope sample is disclosed in Japanese Patent Laid-open Publication No. Hei. 4-282545 (page three, sections three and four, FIG. 1). This method employs an FIB device so that, while an SEM or TEM sample is being subjected to processing, noted observation regions such as defects, etc. present on the same sample can be easily accessed even when a plurality of such regions exist. As shown in FIG. 6, symbols referred to as characters that make the noted observation regions distinctive are processed using an FIB in the vicinity of the area processed using the FIB. Even when it is said that the TEM sample is handled, after implementing thin-processing, this technological theory is based on the problem of, rather than the TEM sample cut-away fixed to the mesh, making specifying the position easier during accessing of the observation slice on a large sample such as a wafer, etc. for processing in a prior processing stage, and as such does not resolve the problem of the difficulty of managing the handling of the TEM sample itself due to the sample being of an extremely small size.
The object of the present invention is to provide a TEM sample equipped with an identifying function for easily specifying a detailed TEM sample and to provide a system for easily managing and handling information relating to the TEM sample using the TEM when making observations that is constructed with the FIB device manufacturing the sample.